1. Field of the Invention
The present invention relates to window shades, and actuating systems used in window shades.
2. Description of the Related Art
Many types of window shades are currently available on the market, such as Venetian blinds, roller shades and honeycomb shades. The shade when lowered can cover the area of the window frame, which can reduce the amount of light entering the room through the window and provided increased privacy. Conventionally, the window shade is provided with an operating cord that can be actuated to raise or lower the window shade. In particular, the operating cord may be pulled downward to raise the window shade, and released to lower the window shade.
In a conventional construction of the window shade, the operating cord can be connected with a drive axle. When the operating cord is pulled downward, the drive axle can rotate to wind suspension cords for raising the window shade. When the operating cord is released, the drive axle can be driven to rotate in a reverse direction for lowering the window shade.
However, this conventional construction may require to use an increased length of the operating cord for window shades that have greater vertical lengths. The greater length of the operating cord may affect the outer appearance of the window shade. Moreover, there is the risk of child strangle on the longer operating cord. To reduce the risk of accidental injuries, the operating cord may be maintained at a higher position so that a young child cannot easily reach the operating cord. Unfortunately, when the operating cord is pulled downward to raise the window shade, the operating cord may still move to a lower position and become accessible for a child. With respect to a regular user, the manipulation of longer operating cords may also be less convenient. For example, the longer operating cord may become entangled, which may render its operation difficult.
To remedy the above disadvantages, certain existing approaches propose a mechanism that can be actuated by repeated pulling actions applied on a cord for raising the window shade. However, these approaches usually need a manual action different from the pulling action for lowering the window shade.
Therefore, there is a need for a window shade that is simple to operate, and address or improve at least the foregoing issues.